Databases Key Terms 0.0 / 5 ? ComputingDatabasesA2/A-levelOCR Created by: ac.x123Created on: 12-12-21 19:01 Primary Key A uniquely identifiable field to identify records within a table 1 of 11 Foreign Key A primary key used in an additional table which connects multiple tables together 2 of 11 Secondary Key An additional field which is assigned and gets indexed for faster searches 3 of 11 Composite Key A primary key made of additional fields 4 of 11 Referential Integrity Consistency to ensure that data removed from a database is not needed elsewhere 5 of 11 Record The individual rows in a table 6 of 11 Field Columns in a table with a specific purpose 7 of 11 Database Structured sets of data organised into tables 8 of 11 First Normal Form Rules Must have a primary key Must have unique field names Must have atomic data (data in its simplest form) No repeated data 9 of 11 Second Normal Form Rules Must be in 1NF All non-key attributes must depend on the primary key (no composite keys) 10 of 11 Third Normal Form Rules Must be in 2NF There can be no non-key interdependencies (transitive dependencies) 11 of 11
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